Before diving in to the rather complicated ethics of the issue of thee-parent embryos, it’s important to dispense with two common misconceptions. First: this isn’t a debate about the rights and wrongs of embryo experimentation. For the time being, that battle has been lost. Secondly: don’t believe the spin. Those who oppose these measures are not anti-science zealots who care more about imposing their faith upon others than life-saving research. Rather, we are highlighting serious concerns that these totally unprecedented and unproven research techniques cross an ethical Rubicon in to the territory of reproductive cloning and germ-line therapy – something we all ought to be concerned about.

Some background is necessary, especially as there is a lot of misinformation around. The dispute centres on ways of curtailing mitochondrial disease through In vitro fertilisation. Mitochondrial disease, broadly speaking, can be described as a failure in cell equipment. The proposal is that those who have faulty mitochondrial DNA in the family could use one of two new IVF techniques to ensure that their child is born without the offending mitochondria. The Department of Health has just launched a consultation outlining how these procedures might be introduced.

On the face of it, this sounds wonderful. Mitochondrial disorders give rise to very serious diseases, and the challenge of living with these conditions must not be downplayed or exploited by either side of the debate. Like any person with an iota of compassion, I am in awe of any scientific breakthrough that stands to alleviate the suffering caused by these diseases.

But the possible benefits of these procedures must be weighed against the ethical consequences of permitting them. The more I learn, the more I am convinced that this is a line we should not cross. Here are just some of the concerns put to me:

We don’t actually know if these techniques work. In fact, there is a growing body of speculative evidence which suggests the contrary: they may actually pose risks to the child. Science Magazine ran a piece recently suggesting that these treatments could cause sterility, and lead to reduced growth, impaired learning and exercise capacity and even a slowed metabolism on the basis that we don’t know if the donor mitochondria will be able properly to communicate with its host. The group Human Genetics Alert agrees: “These techniques go far beyond anything existing in both invasiveness to the embryo and complexity so it’s not surprising that they pose serious health risks to the child, risks that the Human Fertilisation and Embryology Authority refuses to properly address.”

These techniques involve irreversible changes to the human germ line, that is, the way genetic information is transmitted through generations. The Council of Europe’s Convention of Human Rights and Biomedicine explicitly condemns this as does the World Health Organisation which states fairly comprehensively that “where there is an intention or possibility of altering genes passed on to the next generation [this] should not be permitted in the foreseeable future”. Why the HFEA deems itself to be above this advice, I’m not sure. It is truly alarming that Britain is the only country in the world who is on the cusp of permitting these procedures with so little scrutiny, awareness or debate.

These techniques create children with at least three genetic ancestors (or 4 in the case of Pro Nuclear Transfer). By using the core cellular material of three people, the resulting embryo therefore has three ‘parents’ (though it is probably more accurate to speak of ancestry rather than parentage). Those wondering about the ethics of this only need ask themselves a few questions to make clear some attendant identity related issues. Will the child be able to ask questions about or contact their third ancestor? I cannot see any logical reason why they ought to be refused such a request. And what steps will be taken to afford the child the right to know who its parents are? Notwithstanding those queries, what is the precise relation of the child to its commissioning parents? The public deserve to know. Yet these are all unanswered questions.

Full-scale human genetic modification could follow. Mitochondrial DNA only accounts for 0.1 per cent of our total DNA at this stage in life – a fact that is often cited by supporters of this research. But many will argue that there is no reason in principle for objecting to a greater percentage of DNA modification once this threshold were conceded. Make no mistake, the very significant ethical and technological barriers which have restricted these procedures to date are in place for very good reasons.

These techniques are not cures. The pro-research lobby is promoting these procedures as cures, but, they’re not cures at all. Rather than eliminate the disease, they make sure only certain kinds of persons come into existence. After one of the techniques – Pro Nuclear Transfer (PNT) – the child resulting is not the same human individual as the one originally conceived by the commissioning couple. The second technique, Maternal Spindle Transfer (MST), uses genetic manipulation to create an individual purportedly free of known mitochondrial defects – but with what consequences?

We won’t be able to monitor the effects of these procedures in the future. We will only know the long-term effects of MST and PNT in the long-term if we monitor the people who began as PNT or MST embryos and their descendants. But there will be no way to force individuals to participate in such research – nor should there be. Equally, it is surely not the plan of the Government to require MST or PNT adults to disclose to their partners their genetic inheritance (assuming that even they are aware), so the fruits of these techniques – good or bad – may well be totally unknown.

These objections give a flavour of what we’re facing here: untested, unproven, ethically controversial, potentially dangerous techniques which we wouldn’t even be able to monitor. Yet the HFEA is seeking to promote these unsound proposals on the premise that they would establish Britain as a leader of scientific research in this area. Permitting these techniques would represent such a fundamental shift in our concept of family that Parliament should to be given the opportunity to debate – and resist – them.